EP2362099B1 - Self-actuated concentric, crank-side compressor valve - Google Patents

Description

The subject application relates to an automatic compressor valve with a suction valve and a pressure valve, which are arranged concentrically with each other, wherein the suction valve and the pressure valve are arranged radially adjacent to each other and the suction valve and the pressure valve is formed of a first and a second valve disc, between which for Suction valve and the pressure valve each have a sealing element is movably disposed and an application of the compressor valve in a compressor.

In reciprocating compressors, it is known to provide a concentric, arranged in a plane suction and pressure valve on the cylinder head side. Such an arrangement is eg from the DE 1 503 422 A out. Since no separate suction and pressure valves are needed, which require considerably more space than individual parts, the dead space on the cylinder head side can be largely minimized.

For double-acting reciprocating compressors, suction and pressure valves must also be provided on the crankcase side. Since, of course, the reciprocating piston rod must be performed on the crankcase side, the arrangement of suction and pressure valves, especially for a desired small dead space, but much more complicated and difficult.

From the US 4,360,319 A a crank-side valve assembly is shown, in which the suction valve and the pressure valve are arranged radially next to each other about a centrally continuous piston rod, which is sealed by a seal to the crankcase. The suction and pressure valves could of course be arranged on the cylinder wall, but this is associated with a larger dead space.

Alternatively, however, could be arranged on the crankcase side, a concentric suction and pressure valve, such as from GB 249,763 B known. In this valve, the suction valve and the pressure valve are arranged axially one behind the other, which on the one hand causes a great length of the valves and the cylinder itself and on the other hand leads to a large dead space. However, this arrangement also means that the cylinder is complicated and complicated by necessary flow channels. The crank-side pressure valve also surrounds a seal to the piston rod, which is here lapped by the hot compressed pressure medium. The seal is thus additionally heated in addition to the friction heat occurring by the pressure medium unfavorable manner. In addition, this arrangement requires a very complex and therefore expensive valve and cylinder structure.

It is therefore an object of the subject invention to provide a crank side to be arranged, automatic suction and discharge valve, which allows a crank-side installation in a cylinder with the lowest possible dead space and which is simple and compact.

This object is achieved in that in the first and second valve disc an axially continuous recess is provided and a seal of a Number of axially successively arranged pressure packs is arranged axially adjacent to the second valve disc. Through the recess, the piston rod is carried out in operational use, wherein the resulting circumferential gap between piston rod and recess is undesirable dead space. Since the distance between the recess and piston rod can not be arbitrarily reduced, especially since the piston rod is also subjected to movements transverse to the stroke, the circumferential gap (and thus the dead space) is thereby reduced by the axial length of the circumferential gap through the axially on the second valve disc subsequent arrangement of the seal (which limits the circumferential gap in the axial direction) is reduced. This design of a suction and pressure valve with directly connected seal can reduce the dead space accordingly.

The axial length of the circumferential gap and thus the volume of the dead space can be further reduced if at least one pressure pack is arranged in the second valve disc.

It is particularly advantageous if the suction valve is arranged radially inward and a feed space for supplying pressure medium to the suction valve is bounded radially inwardly by the seal. In this case, the seal is surrounded by the cold supplied pressure medium while cooled. As a result, the service life of the seal can be increased or the seal is subject to lower thermal requirements and can therefore be designed simply round (for example with regard to the materials used).

• Fig. 1 eine perspektivische Ansicht eines Schnitts durch ein erfindungsgemäßes Kompressorventil und
• Fig. 2 und 3 eine Ansicht der Verwendung eines erfindungsgemäßen Ventils in einem Zylinder eines Kompressors.

The subject invention will be shown below with reference to the schematic, exemplary, non-limiting and advantageous embodiments FIGS. 1 to 3 described. It shows

• Fig. 1 a perspective view of a section through an inventive compressor valve and
• Fig. 2 and 3 a view of the use of a valve according to the invention in a cylinder of a compressor.

In Fig. 1 is an inventive compressor valve 1 with a suction valve 2 and pressure valve 3, which is arranged concentrically with each other and a seal 20 shown. The suction valve 2 and pressure valve 3 is formed from a first, the cylinder chamber Z facing valve disc 4 and a second, the crankcase chamber K facing valve disc 5, which are arranged axially adjacent to each other. The valve discs 4, 5 are here connected by distributed over the circumference arranged screws 12 to each other, but can of course also be connected by another suitable connection. For the pressure valve 3 is the first valve disc 4 valve seat and the second valve disc 5 valve catcher. For the suction valve 3, the arrangement is reversed, that is, the first valve disc 4 valve catch and the second valve disc 5 valve seat. In the example shown, the pressure valve 3 is arranged radially on the outside and the suction valve 2 radially inward (but this can also be the other way round) and the suction valve 2 and the pressure valve 3 are thus not arranged axially next to one another, but essentially in one plane or radially next to one another. In the valve discs 4, 5, a plurality of flow channels 6, 7, 8, 9 are arranged in a conventional manner to supply or remove pressure medium. Between the first and second valve disk 4, 5 (or between the respective valve seat and valve catcher), a respective sealing element 11, 10 movably arranged in the axial direction is provided for the suction valve 2 and the pressure valve 3. A sealing element 10, 11 can also be pressed in a known manner by spring elements, such as coil springs, which are arranged in the respective valve catch, or by spring plates between the valve catcher and sealing element against the respective valve seat.

The sealing elements 10, 11 are designed here as sealing plates, which have a plurality of flow-through channels in a conventional manner. The sealing elements 10, 11 are each guided radially inward at an axial step of the second valve disc 5. Alternatively, a sealing element 10, 11 but also be designed in the form of individual concentric sealing rings. Likewise, the radial and axial guidance of the sealing elements 10, 11 can be designed differently, e.g. through guide lugs on the valve seat.

The sealing elements 10, 11 may have a planar (ie, in a normal plane to the axis of the compressor valve 1) sealing surface. However, the sealing elements 10, 11 may also have profiled sealing surfaces, such as e.g. Beveled edges, torically formed sealing surfaces or other arbitrarily shaped sealing surfaces. The associated sealing surfaces on the respective valve seat are formed opposite.

On the valve disks 4, 5, an axially continuous recess 13 is provided radially inwardly through which a piston rod 35 is performed in the operational use of the valve (see Fig. 2 ). To avoid contact and thus wear and generation of friction or frictional heat between the piston rod 35 and recess 13, the recess 13 should be spaced from the outer peripheral surface of the piston rod 35. However, this results in a circumferential gap 36 between piston rod 35 and recess 13, whose volume forms dead space. It is therefore desirable to keep this circumferential gap 36 as small as possible. The radial distance to the piston rod 35 out but can not be made as small as possible, since the piston rod 35 is also subjected to radial movements (or transverse to the lifting movement).

In order to minimize the circumferential gap 36, closes the seal 20 of the piston rod 35 to the crankcase according to the invention axially to the second, the crankcase K facing valve disc 5 of the compressor valve 1 to keep the axial length of the circumferential gap 36 as low as possible. This seal 20 typically comprises a number of pressure packs 21 arranged axially one behind the other, e.g. formed in a known manner from radially and / or tangentially cut or segmented packing rings 22 possibly in combination with support rings, which are arranged in a chamber disk 23. The seal 20 could also, at one end face or both sides, also have an axial termination, e.g. in the form of an annular disc. Such seals 20 of a piston rod 35 are well known and it will not be discussed further here in consequence.

Preferably, the seal 20 is arranged as close as possible to the cylinder-side axial end of the compressor valve 1, as this further reduces the radial length of the circumferential gap 36. For this purpose, it is provided here to arrange at least a first pressure pack 21 a in the second valve disc 5. It is also conceivable to arrange further pressure packs 21 in the second valve disk 5. For this pressure pack (s) 21 a can also be dispensed with a chamber disc 23, whose function can take over the second valve disc 5. The closer this first pressure pack 21 a is arranged at the cylinder-side end of the compressor valve 1, the further the axial length of the circumferential gap 36 can be shortened and the smaller is the dead space.

For fixing the seal 20 to the compressor valve 1, a holding plate 25 is provided in the embodiment shown, through which distributed over the circumference, screwed into the second valve disc 5 bolts 26 lead. The holding plate 25 is pressed by means of nuts 27 against the seal 20, which is thus attached to the compressor valve 1. The compressor valve 1 can thus be completely pre-assembled and then used as a component in the cylinder, which greatly simplifies the assembly. But also a subsequent installation of the seal 20 and a simple maintainability of the seal 20 is thus made possible.

The Figs. 2 and 3 show the compressor valve 1 according to the invention in use in a cylinder 31 of a double-acting compressor 30. In a cylinder 31 of the compressor 30, a piston 34 which is connected to a piston rod 35 is reciprocated. The cylinder 31 could also be designed as a bushing. The crankcase 32 is separated from the cylinder 31 by a partition wall 33. At this partition 33, the compressor valve 1 according to the invention is attached here. For this purpose lead through the partition wall 33 distributed over the circumference, a number of bolts 37, which are screwed into the compressor valve 1, here in the second valve disc 5. The compressor valve 1 can then by nuts 38 are attached to the partition wall 33. The holding plate 25 may also be arranged in a recess of the partition plate 33, wherein on the holding plate 25, a suitable sealing element, such as an O-ring, may be provided to the partition plate 33.

The piston rod 35 is passed through the recesses 13 of the compressor valve 1. The seal 20 surrounds the piston rod 35 and seals the cylinder chamber Z against the crankcase chamber K.

In the wall of the cylinder 31 are feed openings 38 through which pressure medium, e.g. Air, is supplied to the suction valve 2, provided. The supplied pressure medium is guided between the second valve disc 5 and partition wall 33, wherein the feed space 40 formed thereby is bounded radially inwardly by the seal 20. Furthermore, 31 discharge openings 39 are provided in the wall of the cylinder, through which the compressed pressure medium flowing through the pressure valve 3 is discharged. Preferably, a plurality of feed openings 38 and / or discharge openings 39 are provided over the circumference.

Due to the fact that the feed space 40 is bounded radially inwardly by the seal 20, the cold supplied pressure medium flows around the seal 20 and at the same time cools the seal 20. As a result, the life of the seal 20 can be increased or the seal 20 is subject to lower thermal requirements and therefore it can be simple and cheaper.

The dead space between the piston 34 and the first valve disk 4 can be largely minimized by the piston 34 is adapted to the shape of the cylinder chamber Z facing axial end face, which is preferably configured just the first valve disk 4. The distance between the first valve disk 4 and the piston 34 can be reduced to such an extent that no contact takes place between the piston 34 and the compressor valve 1 during operation.

Cylinder head side is here also a concentric suction and pressure valve 50 is arranged, which can be controlled via a Abhebegreifer 51. Also on the crank-side compressor valve 1, a lift-off gripper can be arranged, e.g. protruding laterally through the cylinder 31, or from below through the crankcase chamber K.

Of course, the compressor valve 1 according to the invention can also be used in a single-acting compressor, in which case the compressor valve 1 according to the invention would be the only valve on the cylinder.

Claims (5)

1. An automatic compressor valve with a suction valve (2) and a pressure valve (3) which are arranged concentrically to one another, wherein the suction valve (2) and the pressure valve (3) are arranged radially adjacent to one another and the suction valve (2) and the pressure valve (3) are formed from a first and a second valve disk (4, 5) between which a sealing element (10, 11) is movably arranged for the suction valve (2) and the pressure valve (3), characterized in that in the first and the second valve disk (4, 5), an axially continuously open recess (13) is provided and that a sealing (20) consisting of a number of pressure packings (21 a, 21), which are arranged axially one behind the other, is arranged axially abutting on the second valve disk (5).
2. The automatic compressor valve according to claim 1, characterized in that at least one pressure packing (21 a) is arranged in the second valve disk (5).
3. The automatic compressor valve according to claim 1 or claim 2, characterized in that the suction valve (2) is arranged radially on the inside and a supply chamber (40) for supplying pressure medium to the suction valve (2) is bordered radially on the inside by the sealing (20).
4. A compressor (30) with a cylinder (31) and a crankcase, wherein the crankcase is separated from the cylinder (31) by a separating wall (33), and an automatic compressor valve (1) according to any one of the claims 1 to 3 is arranged on the separating wall (33), and a piston rod (35) of the compressor (30) is guided through the recess (13) of the first and second valve disk (4, 5) and is surrounded by the sealing (20) for sealing between cylinder space (Z) and crankcase (K).
5. The compressor according to claim 4, characterized in that in the wall of the cylinder (31), a number of supply openings (38) for supplying pressure medium and/or a number of discharge openings (39) for discharging pressure medium are arranged.

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